Grading and supplying system for abrasives



W. L. AND R. G. KANN. GRADING AND sumvmc svsnm FOR- ABRASIVES.

APPLICATION FlLED FEB. 23. l9l8. I 7 1,321,528, PatentedNov. 11, 1919.

. 2 SHEETS-SHEET WITNESSES w. L. AND R G. KANN. GRADING AND SUPPLYING SYSTEM FOR ABRASIVES.

APPLICATJON FILED FEB. 23. I918.

Patented Nov. 11, 1919.

so \\\i INVENTORS 2 SHEETS-SHEET 2.

MWMSS W WITNESSES W QM G UNITED STATES PATENT WILLIAM L; KANN AND :aALrn G. KANN, or rrr'rsnuaen, rmsrnvmn.

enenme AND surrLYme SYSTEM nor. am.-

Specificationof Letters Patent. Patented Nov. 11,; 1919 Application filed February 2a, 1918. Seria11i'o. 218,624.

To all whom it may concern Be it known that we, VILLIAM L. KANN and RALPH G. Kann, both citizens of the United States, residing at liittslourgh Allegheny county, Pennsylvania, have invented a new and useful Improvement in Grading and Supplying Systems for Abrasives, of

which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is a plan view, largely diagrammatic, of. apparatus embodying our invention.

Fig., 2 is a longitudinal vertical section of the grading apparatus, the plane of section on the line 11-11 of Fig. 3.

Fig. 3 is a plan view, of the apparatus Figs. 4 and 5 are sections taken respec- Figs.-2 and 8; and g Fig. 6 is a fragmentary plan view showing a'modified construction of grading box.

Our invention has relation to apparatus for use in grading and supplying sand,'or other abrasive, or to grinding machines, such as plate glass grinding and smoothing machines.

The invention is designed to provide a grading and supplying system for abrasives, such as sand, by which the used abrasive coming from the grinding machines may be graded with a high degree of uniformity,

and the successive grades collected for delivery back to the machines for further use as required. It is also designed to provide a system of this character which will be highly economical in its use of abrasive by enabling the coarse abrasive delivered to the machine for any particular coarse grinding operation to be used up to a maximum extent during the subsequent finer v grinding operations, thereby conserving all th. useful particles of the abradant.

A still further object of the invention is to provide a system in which the abrasive too fine for further use, together with dirt and slims, is effectively separated out, thereby getting the full benefit of the abradant at each step of the operation, and in which the several operations may be easily controlled as may be necessary to meet the various conditions which arise in practice. A still further object'is to provide a system in which the apparatus employed 1s simple in its character and construction and not.

- likely to get out of order; which can be installed and maintained at arelatively low 1 cost, and which will not skilled labor.

In general, our invention provides a'sys-. tem of the described character, the use of which results in an increased output of superior product from the grinding machines in connection with which it is employed.

Our invention will be described as applied to apparatus for grading and supplying sand to plate glass grinding machines;.but it will be understood that-our invention is not limited thereto, and the term sand as used herein and in the appended claims is to be understood as including anymther require the use of eomminuted or-granulated 'abradantwhich may be employed in systems of, character. s p

Referring to the accompanyingt in which we have shown a preferred jembodiment of our invention, the numeral 2 designates a plate glass grinding machine of any usual or suitable character, having the usual grinding runners 3,,and which is sur rounded by a ditch 4 into which the water and abrasive discharged from the machine is collected. 5 d'esigriatesa new coarse sand supply, whiclimay be ofany'suitable character, such as a sump or well of the character described and claimed in the co-pending application of William L. Kann, one of the present applicants, Serial No. 834,102,- filed April 24, 1914. The new coarse sand delivered to this sump or well is washed therein and is delivered to the machine by apipe6. I

7 designates a relatively shallow pit located at one side of the grindin machine and at a lower level than the tab e thereof. This pit is formed with two reversely inclined longitudinal gutters -7 and 7", the gutter 7 forming an outlet which may lead directly to a sewer (if the grade is such as to permit this) or which discharge into a sump 8 from which the water, etc., may be removed in any' suitable manner, forming no part'of the invention; The gutter 7"- is inclined toward the receiving end of the pit 7, to a conduit 7 which discharges into a well or sump 24 hereinafterdescribed.

Placed in one end portion either pit 7 is a used. sand box or receptacle 9nto which the used sand and water from the grinding machine flows from the ditch t and conduit 10. 11 is a screen which is preferably employed Where the conduit discharges into said box 9 for the purpose of screening out any coarse foreign matter. The used sand box 9 is provided with an outlet at one end, controlled by an adjustable dam or weir 12, this outlet or overflow leading into a sluice-way 13 which conducts the sand and water to the seriesof grading boxes l4, 15, 16 and 17. These grading boxes are arranged in tandem, the overflow from one box passing into the next "adjacent box, over the intermediate partitions 18 which are made independently adjustable as to height. Each of these boxes, is shown as having inclined side and bottom walls2l converging toward a bottom outlet opening 22,

. arranged to discharge into the gutter 7 of the pit 7, leading to the well or sump 2% which is underneath the used sand box 9. Each of the discharges 22has a separate valve 23 by means ofwhich it may be controlled. The used sand box is also provided with a valved bottom opening 25 discharging into the gutter 7*. It is also provided with anadjustable overflow 26, at one side, arranged to dischar e into the sewer connection 7%. Each 0 the grading boxes 14,

15, 1'6 and 17 is also preferably providedwith a valved outlet 27 located in one side of thebox near its top, and arranged to. discharge into said sewer connection 7*,

gate 27, and arranged to discharge into the gutter 7 28 designates any suitable pump by means of which sand and water from the pit or sump 2.4 may be returned to the grinding table for reuse. 29 is an overflow leading from the upper portion of said pit or sump into the sewer connection 7 and forming a means of holding constant head of water in pit or sump 2%, by which means a practically constant volume of water is had for grading. 30 designates any suitable system of water pipes by means of which water ,i'nay be introduced into the grading boxes 14, 15, 16 and 17. The last grading box 17 is provided with an adjustable overflow 31 leading into a box 32 having a dis-- charge opening leading into the sewer connection 7 and controlled by an adjustable gate 33.

The operation of the system is as follows: New coarse washed sand is supplied to the table; the grinding machine is started and new sand is ground under the runners 3 and is thrown by centrifugal action into the table ditch 4. From this ditclf it is conveyed into the used sand box 9. Vii/ hen this box becomes filled with sand and water it.

overflows into the sluice-way 13, and thence into and over the series of grading boxes. ,There is deposited in each box its proper grade of sand by reason of the different '24 onto the table. I water serves for wash-out purposes. In the The opposite side of each of these boxes has a discharge opening controlled by :1"

specific gravities ofthe sand. It is desirable to so regulate the supply of water to the system that there will be substantially 'oonstant volume of flow over the tops of the series oi grading boxes so that the grading action will be substantially uniform at'all boxes may be largely. regulated by means I of the adjustable overflow at 12 and 26.

As soon as sufficient new coarse sand has been applied to the machine to effect the coarse grinding operation, the supply of this sand is shut off. The valve controlling the discharge 25 from the used sand box 9 is then opened, and sand and water from this box pass into the gutter 7 and thence into the well or sump 2%, from which it is pumped up and delivered hack to the table through the pipe After again passing under the runners it flows back into the used sand box 9.. This cycle of operation.is ,continued until all of the sand coarseenough to deposit in the box 9 is used'np and on y practically clear water passes from the bot tom discharge of said box and from the pit This substantially clear meanwhile, and during the course of this continuous cycle, the fine sands have been properly graded out and delivered in the series of grading boxes 14, 15, 16 and 17.

While the machine is being washed out, the valves of the discharges 27 from said boxes are preferably opened in order to allow surplus water to flow from the boxes into the sewer connection. When the machine -is washed out the bottom. discharge valve 23 of thefirst grading box 14.- is opened and fine and the grinding of the side ofglass is completed.

Immediatelybefore the first grade of fine sand from the box H is started in use, the overflow from the used sand boxinto the sluice-way 13 is closed by means of a gate 12, so that water and any contained slimes too fine for use coming back from the table will be caused to overflow into the ditch 7, 1

the bottom discharge valve 25 of the box 9 being also closed. I I

The pump which returns the sand from the well or sum p 24 to the machine is run at substantially constant speed (orpressure,

' time that the used sand'from the box 9 is going to the table.

if an air-lizft pump ,is employed) in order to regulate the amount of water in the system .and keep it-constant', the regulating means,

of course-,dependhg on the type of pump employed andthe means of actuating the same. ,The overflow 29 from the upper portion or the well or sumpQA not only causes" the constant discharge of all useless slimes, etc.,-as conducted thereto, butfalso acts to maintain aconstant head and pres.- sure of water in thewell. This is of particular importance'where an air-lift pump is employed. I

Tt will be noted that each original batch of new coarse sand supplied to the machine.

is used up without waste during theoperations of rough grinding and smoothing and finishing, the supply of sand for the last named operations being furnished in proper quantity and in the required successively finer grades from the sand which has accumulated in the grading boxes during the time that new fresh coarse sand is being supplied to the table, aswell as-during the It will also be noted that in the describe operations, there is at no time any admix-- ture of used sand with new coarse sand supplied to the table.

By the-arrangement of grading boxes described whereby all of these boxes, to gether with the used sand box, is caused to discharge into a single pit or sump 24, only one pump is required to deliver the successive grades of sand from such boxes to the table. The several overflows provide means for freeing the system of slimes andsand too fine for further use, thus'maintaining the sand which goes to the table in clean I condition.

In some cases, it, may be'desirable to stop the flow to the table of any particular grade of sand before all the sand of that grade has been removed from the pit 24/ This can be readily accomplished by providing the pipe 34 with a valved branch 35 which m'ay'have a flexible portion 36 therein. By

. closing the valve 37 in the pipe 34 beyond its branch, the sand raised by the pump may be delivered either into the used sandbox through such branch or returned to the proper grading box.

Should it be desired at any time to make grades of finer sands (for instance, for regrinding) either from new coarse sand, or

from used sand, without operating the using apparatus, this can be readily done as fol-. lows:

The connection to the gutter 7 a through the box 32 and gate 33 is closed, and a gate 33 provided at, the opposite side of the box 32 and controlling an opening arranged to dis charge into the gutter 7-, is opened. It recgradmg of a portion of the sand 1n the grading boxes is necessary, the gate 27 of such box. or .boxes is also opened, and the material contained therein directed back into the well or sump 24. The used-sand box 9 is supplied with new coarse sand or with used sand, with the necessary watery. By means of the flexible pipe connection 35 and .valve 37, the sand from the well or sump24' may be returned to the used sand box, or to any one of the grading boxes. The waste slimes and excess water are dis-' posed of through the overflows 29 and gut-' tor 7. The grading in this operation is controlled by the constant head in the well-or sump 24 maintained by its overflows; by the substantially constant rate of discharge through the. pump 28, and by thelsubstantially constant volume of horizontal .flow over the grading boxes. Y 1 In Fig. 6 I have shown a construction of grading boxes in which one of the side walls 7 38 may be adjusted toward or away from each other to thereby vary the cross sec.- tional area of the box;

-We desire it understood tion is not limited to the particular con various changes may be made therein within.

that our invenstruction, arrangement or combination or:

parts herein shown and described but that-= the spirit and scope ofthe appended claims,

thus, the grading boxes may be of any suitable construction; the overflows may be differently arranged. The material to be graded may be either a used abradant as herein specifically described, or it may be a new abrasive which it is desired to grade.

Such abrasive may be supplied to the system in anyv suitable 1113111161.,1601' instance, directly into the sum 24; and the graded material instead of being delivered 'immedi-' ately back to 'a using apparatus, may be placed in storage or removed for use at distant points, and various other changes may ceive the overflow of abrasive and Water from the used sand box, a well or sump,

means whereby the abrasive may be separately discharged from the usedsand box and from the several grading boxes into said Well or sump, and means for returning I sand and water from said Well or sump to,

apoint of use; substantially as described.

- boxes at a lower level than the source of supply of used sand and arranged to re" 2. In apparatus for grading andsupply ing sand, the combination of a useds'and receptacle, means for supplying used d to said receptacle, a system of grading boxes at a lower level than the source of supply of. used sand and arranged to receive the.

overflow of abrasive and "water from the used sand box a Well or sump, means where by the abrasive may be separately discharged from the used sand box and from the several grading bo xes into said well or sump, and means for returning the sand andwater from said Well or sump to a place of use or to the used sand box; substantially as described.

In apparatus for grading and supplying sand, the combination of a used sand to ceptacle, means for supplying used sand to from said sump and delivering it to a place of use, together with means for controlling the volume of flow-over the grading boxes; substantially as described.

4. In apparatus for grading and supplying sand, the con'ibination of a used sand receptacle, means for returning the used sand from a place of use to said receptacle, a system of grading. boxes at a lower level than the source of supplyof used sand and arranged to receive the overflow of abrasive and water from the used sand box, a sump, means whereby the abrasive may be separately discharged .from the used sand box and from the several grading boxes into said sump, and means for returning sand and water from said sump to the place of use, together with means for varying the capacity of said boxes; substantially as described.

In apparatus for grading and supplying sand, the combination of a used sand receptacle, means for returning the sand from a place of use to said receptacle, a system of grading boxes at a lower level than the place of use and ar 'anged toreceive the overflow of sand and ,water from the used sand box, said overflow being arranged to travel over the said boxes, a Well or sump, means wherebythe sand may be separately discharged from the used sanl box and also from any one of the grading boxes into said sump, and means for raising sand and water from said sump and delivering it to. the place of useytogethcr with means for controlling the volume of flow over the grading boxes, together with means for varying the height of overflow between successive boxes;

substantially as described.

6. In a sand grading and supplying system, a pit, aused sand box in said pit, a conduit for conducting the used abrasive and water into the used sand box, a series of grading boxes in said pit connected to the used sand box and arranged to receive the overflow by gravity therefrom, a sump into wh1ch the used sand box and the grading boxes are. arranged to discharge, and means for returning the sand from said sump to a place of use, said boxes also each having a controllable overflow, and a conduit arranged to receive the discharge from said overflows, substantially as described.

7. In a sand grading system, a pit located below the level of the source'of sand supply, a series of grading boxes located in said pit, means for causing a gravity flow of the sand over said boxes, a sump connected with. the pit, means whereby the contents of the several boxes may be successively discharged by gravity into the pit and thence into the sump, substantially as described.

8. In a sand grading system, a pit located below the level ofthe source of sand supply, a series of grading boxes located in said pit,.means for causing a gravity flow of the sand over said boxes, a sump connected with the pit, and each of said boxes having a bottom discharge into the pit and thence to the sump, and another discharge at a higher level into said pit and sump, together with valve means for separately controlling said discharges, substantially as described.

9. In a system of the character described, a pit located below the level of the source of sand supply, said pit having a sump therein and also two gutters one leading into the sump and one leading therefrom, and a system of grading boxes having means for discharging their contents into either one 01 .sa1d gutters, together with an overflow rcceptacle at the end of the system of grading boxes, and means wherebysaid receptacle may be made to discharge into either of said gutters, substantially as described.

10. In a sand grading system, a pit having two bottom gutters, one leading to a waste outlet, at deep sump into which the other gutter discharges, and a series of grading boxes in said pit, each of said boxes having a waste overflow arranged to discharge into the first named gutter, and a bottom outlet, arranged to discharge into the second gutter, and a box into which the last grading box is arranged to overflow, said box having a controlled outlet to both gutters, substantially as described.

In testimony whereof We have hereunto set our hands.

W. L. KANN. RALPH G. KANN. 

